Welt-trimmer



- (NoMddeL) P. A. DUNHAM.

WELTTRIMMBR. No. 527,950 Patented Oct. 23,1894.

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NITED STATES ATENT FFICE.

WELT-TRIMMER- SPECIFIGATIONforming part, of Letters Patent No. 527,950, dated. October 23, 1894. Application filed July 18, 1894. Serial No, 517,903- (No model.)

To aZZ whom it may concern:

Be it known that I, FRANK A. DUNHAM, of Brockton, in the county of Plymouth and State of Massachusetts, have invented certain new and useful Improvements in Welt-Trimmers, of which the following is a specification.

This invention relates to welt trimmers employing a segmental blade which is clamped against a seat on a supporting shank or stock, said seat having at its margin an outwardly projecting flange or wall of segmental form which is parallel to the outer edge of the segmental blade.

The invention has for its object to provide means for securely clamping the blade to the stock in such manner as to prevent its accidental displacement when in use; and to this end it consists in the combination with the stock having the segmental wall or flange at the outer margin of the blade seat, of a blade having its outer edge formed to [it said wall, and an attaching screw having a head or washer adapted to exert an outward lateral pressure upon the inner segmental edge of the blade, thus not only forcing the inner side of the blade laterally against the seat, butalso forcing the outer segmental edge of the blade against the wall or flange at the outer edge of the seat, as I will now proceed to describe.

Of the accompanying drawings, forming a part of this specification,-Figure 1 represents a side elevation of a Welt trimmer pro vided with my improvement. sents a section on line 2-2 of Fig. 1. Fig. 3 represents a perspective view of the segmental blade.

The same letters and numerals of reference indicate the same parts in all the figures.

In the drawings-a represents the segmental blade having the outer segmental edge or back, 2 the inner segmental edge 3; and the sharpened cutting edge 4:- i

b represents the stock or shank to which the blade is affixed, said stock being here shown as secured to a handle 0 in the usual or any suitable manner. The stock is provided in one side with a recess, the bottom 5 of which constitutes a seat which fits the inner side of the blade, While the margin 6 constitutes a segmental wall or shoulder which fits the segmental outer edge of the blade or that portion thereof which is contained in said recess.

Fig. 2 repre- 0 represents an attaching screw which is engaged with a tapped socket in the stock I),

blade and to exert pressure upon said edgein such direction as to simultaneously press the blade inwardly against the seat 5, and edgewise against the wall 6. The head 0' is preferably a washer made in a separate piece from the screw and bearing against the inner side of the usual head 0 of the screw. I do not limit myself to this construction, and may make the head 0' an integral part of the screw. 4

The result above described, namely, the sidewise pressure of the blade against the seat 5, and the edgewise pressure thereof against the wall 6, is best accomplished by making the margin? of the head 0' tapering or frusto-conical, as shown in Fig. 2, so that when pressed inwardly by the screw said margin will act as a wedge to force the blade at outwardly against the Wall 6.

It will be seen that the blade is thus firmly secured to the stock, so that there will be no liability of its being moved edgewise by any pressure which can be exerted upon it in the operation of the tool, the blade having not only the extended bearing of its inner side against the seat 7, but also the elongated bearing of its outer edge against the wall 6.

I claim- A welt trimmer comprising in its construction a stock or shank b having a seat 5 and a segmental wall 6 at the outer margin of said seat, a segmental blade a having a curved outer edge 2 adapted to bear against said wall, and a curved inner edge 3, a washer having a beveled edge bearing on the inner edge 3 of the blade, and an attaching screw.

bearing on said washer, the latter being formed to simultaneously exert sidewise pressure on the blade whereby its inner side is forced against the seat 5, and edgewise pressure on the blade whereby its outer edge is forced against the wall 6.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 14th day of July, A. D. 1894.

FRANK A. DUNHAM.

Witnesses:

O. F. BROWN, A, D. HARRISON.

IOO 

